Adding machine



June 3, 19.41. L.. J. RITZ 2,243,884

ADDING MACHINE Filed Dec. 7, 1939 2 Sheets-Sheet l m wj June 3, 1941. J.RlTZ 2,243,884

ADDING MACHINE Filed Dec. 7, 1939 2 Sheets-Sheet 2 .20. g 2 5 QQZZJOP JI ll 22 M RNEY Patented June 3, 1941 ADDING MACHINE Linus J. Ritz,Pittsburgh, Pa., assignor to Wolverine Supply and Manufacturing Company,Pittsburgh, Pa., a corporation of Pennsylvania.

Application December 7, 1939, Serial No. 308,010

2 Claims.

This invention relates to adding machines, and the principal purpose inview is the provision of such a machine which may be cheaplymanufactured and sold at a relatively small cost, but which will beconvenient and simple to use, durable in construction, and which willassure accurate mathematical results.

Another object is the provision of an adding machine which may beembodied in small compass and which may be sold as a useful article foruse in the entertaining instruction of children.

In the accompanying drawings, wherein is illustrated a practicalembodiment of the present invention,

Fig. 1 is a plan view of the adding machine;

Fig. 2 is an enlarged longitudinal section of the machine taken alongthe line 2-2 in Fig. 1;

Fig. 3 is an incomplete view similar to Fig. 2 but sectioned on aparallel plane;

Fig. 4 is a perspective view of one of the operating slide bars;

Fig. 5 is a sectional view of the same taken along the line 5-5 in Fig.4.

Fig. 6 is an inverted plan view of the machine on enlarged scale andwith the bottom removed to show parts.

Fig. '7 is an enlarged plan view of the machine with the cover removedto show parts.

Fig. 8 is an enlarged cross sectional View of one of the sliding barsand its mounting.

Referring in detail to the drawings, Ill represents a box, preferablyrectangular and formed of sheet metal or other similar material, andprovided with a bottom II, vertical walls I2 and forwardly anddownwardly inclined floor or top wall I3.

Spanning the front portion of the interior of the box III are twoparallel shafts III and I5 having their ends received in the side wallsof the box.

Both of these shafts are below the plane of the floor I3 of the box andthe front shaft I5 is positioned at a lower level than the rear shaftRotatably mounted on the rear shaft I4 and in spaced relation are aplurality of indicator wheels generally indicated by the numeral I6 anddistinguished as IBa, I61), I60 and I6d. The wheels are preferablycup-shaped with the outer surfaces of their perimetral flanges providedwith a consecutive series of numerals from 0 to 9 inclusive, arrangedcircumferentially of the wheels.

Any desired number of said disks may be provided to give the desiredworking capacity of the machine. In the machine illustrated in thedrawings four of the indicator disks are provided, and the machine isarranged to add up to 9999.

Each of the wheels I 6 is provided with a tubular hub, indicated at Ila,I12), I10 and lid, respectively, by means of which the wheel isrotatively mounted on the shaft I4. One end of each hub, the right endlooking from the front of the machine is provided with a relativelysmall star gear I8 having ten teeth and the other end of the hub isprovided with a gear l9 of larger diameter than the gear I8, but of lessdiameter than the disk I6, and also provided with ten teeth.

Rotatably mounted on the front shaft I5 are a series of spaced aparthubs 20a, 23b, and 200 which are in staggered relation to the hubs Ila,Ilb, I10 and ild on the shaft I4. On one end of each hub 29 is rigidlymounted the star gear 2| having ten teeth and at the other end of thehub a single-toothed gear 22.

The gears 2| of the hubs Ma, 20?) and 200 are in continuous mesh withthe gears I9 of the hubs Ila, Ill) and I'Ec, respectively, while thesingletoothed gears 22 of the hubs 20a, 20b and 200 are arranged toengage once in every complete revolution the gears I8 of the hubs I'Ib,I10 and H11, respectively, and thus with each complete revolution of theindicator wheel IGa, the indicator wheel I 6b is rotated a tenth of arevolution; when the indicator wheel I51; completes a full revolution,the indicator wheel I60 is advanced a tenth of a revolution, and whenthe indicator wheel I completes a full revolution the indicator wheelISd is turned a tenth of a revolution.

The gears 2| and 22 are provided at either side with the shrouds 23between which the teeth of the gears I8 and I9 extend, and thus thegears on the shafts It and I5 are maintained in proper alignment witheach other.

The peripheral portions of the wheels I6 and the gears I9 extend upthrough a transverse opening 24 in the floor I3.

25a, 25b, 25c and 25:! indicate a series of sliding bars equal in numberto the indicator wheels I6, and moving on the surface of the door I3 andeach in alignment with but above one of the gears I9 respectively. Thebars are resiliently retracted upwardly or rearwardly as by the helicalsprings 26 whose rear ends are attached to the underside of the floor I3adjacent the rear end of the same, and whose forward ends are attachedto the fingers 21 extending forwardly from the front ends of the bars,the floor being cut away for clearance for the front portions of thesprings as shown at 28.

The cross sectional shape of the bars 25 is that of an inverted channelwith the edge flanges provided with an intermediate longitudinalshoulder 29.

30 indicates a series of equally spaced holes out in the shoulder 29 andflange at one side of each bar 25 and having their rear end walls bentoutwardly to form a rack arranged to engage the teeth of thecorresponding gear 19 so that as the bar is slid downwardly andforwardly on the fioor i3, against the influence of the helical spring,the gear and the corresponding indicator wheel will be rotated to anextent corresponding to the length of the movement of the bar. When thebar is released and is spring returned, the rack travels rearwardlywithout rotating the gear and Wheel in a reverse direction. The bars areprovided with finger holes 3| in their top wall arranged longitudinallyof the bar and so positioned and spaced apart that when a finger or apencil is engaged in one of the holes and the bar moved downwardly tothe limit of its travel, the gear and wheel will be rota-ted to thecorresponding degree.

The indicator wheels ii; are arranged for revolution in acounterclockwise direction in Fig. 3 and to prevent accidental reverserotation a spring metal plate 32 is secured to the underside of theT1001 13 in the rear of the opening 24 in the floor, and 33 indicatesspring fingers which extend forwardly and engage the gears l8 to preventreverse rotation of the latter. Also there are provided the spring metalstrips 34 which have angular arcuate extremitie which form shoes 35 toengage the inner surfaces of the perimetral flanges of the indicatorwheels IE to act as brakes to prevent the wheels from excess movement orspinning when they are rotated by the movement of one of the slide bars.

The material of the floor 13 at the front of the opening 24 is bentdownwardly, forming a flange 36 having at its free edge the broadfingers 3?, which extend between the exterior shrouds 23 of adjacenthubs, thus preventing movement of the hubs I7 and 29 in the shafts l4and I5, and thus preventing misalignment of parts. The floor i3 forwardof the opening 24 is also slotted longitudinally as at 4 3 to provide vclearance for the springs 25 as the slides 25 approach the limit oftheir forward travel.

38 indicates the pressed metal cover which is provided with a perimetraledge flange 39, whose lower edge is beaded, to engage the floor l3 andhold the cover in upwardly spaced relation to the floor.

The cover is provided with a transversely disposed series of holes t6which register with the tops of the wheels It to expose the numerals atthe tops of said wheels so that the total indicated can be read.

The cover is also provided with longitudinally elongated openings 4!exposing the tops of the bars 25 when the latter are in their upwardlyretracted position, and along one side of each of said openings isdisplayed a series of numbers from to 9 inclusive progressing rearwardlyof the machine, and each of said bars is provided with a correspondingnumber of the finger holes 3| which when the bars are retracted registerwith the corresponding numerals on the cover. The limit of downward orforward movement of the bars is provided by the lower ends of theopenings 4|, as the finger or pencil will engage such end to halt theforward movement of the bar.

The arrangement is such that when the finger or pencil is engaged withthe first hole at the lower end of the bar 25 and the bar is movedforwardly to the limit of its travel, the corresponding indicator wheelI6 is rotated one-tenth of its full revolution, and likewise in whateveropening in the bar the finger is placed and the bar moved downwardly tothe lower extremity of its path, the corresponding wheel i6 is rotatedto the fraction of its complete revolution indicated by the numeral onthe cover registering with that particular opening in the bar when thebar is retracted to its uppermost position.

Again as the total of digits registered on the wheel lGa reaches ten,that wheel indicates 0, while the second wheel [6b is rotated a tenth ofa revolution and indicates 1. When the total registered on the wheel ltbreaches ten, that wheel registers 0 and the Wheel I60 is rotated a tenthof a revolution to indicate 1. Likewise when the total indicated onwheel l6c reaches ten, the wheel l6d is rotated a tenth of a revolutionand indicates 1. Thus the increasing total of a sequence of additions isindicated on the wheels up to the limit of nine thousand nine hundredand ninety-nine. By the provision of additional wheels the maximum totalwhich may be registered may be increased as desired.

The bars are held against excess upward movement in response to theinfluence of their helical springs by means of a fiange 42 partially cutout and struck up from the floor l3.

The bars are held against lateral movement from their proper paths bymeans of the downwardly flanged edges 43 of the openings 4| in thecover, which edges are slidably engaged from below by the shoulders 29of the bars.

In cases where the adding machine is to be used to add sums of moneyincluding fractions of a dollar, the first two wheels at the right ofthe machine may be used for adding and indicating the cents, and theremaining wheel to the left for indicating the dollars.

It is apparent from the foregoing that the adding machine hereinillustrated and described is of simple yet rugged and durableconstruction and is accurate in the mathematical results obtainedthereon. Also it may be manufactured for sale at a relatively smallprice.

I claim:

1. An adding machine slide comprising a U- shaped channel member, theside flanges of the channel member being offset to produce shoulderslongitudinally thereof, spaced digit openings in the web portion of thechannel member for receiving means to move the slide, and a gear rackformed in the offset shoulder along one side of the channel member.

2. An adding machine slide comprising a U- shaped channel member, theside flanges of the channel member being offset to produce shoulderslongitudinally thereof, spaced digit openings in the web portion of thechannel member for receiving means to move the slide, and a gear rackformed longitudinally of the channel member.

LINUS J. RITZ.

